Automatic desludging apparatus



Sheet ATTORNEYS.

June 10, 1969 H. HEMFORT AUTOMATIC DESLUDGING APPARATUS Filed sept. 15, 196e 9 'Y Heim-mh Hem-fart.

H. HEM FORT AUTOMATIC DESLUDGING APPARATUS `lune 10,` .1969

sheet 2 @f2 Filed Sept. 13, 1966 FIG.

y INVENTOR: Heinrich Hem BY:

ATTORNEYS.

United States Patent O AUTOMATIC DESLUDGING APPARATUS Heinrich Hemfort, Oelde, Westphalia, Germany,'assignor to Westfalia Separator Aktiengesellschaft Oelde, Westphalia, Germany, a corporation of Germany Filed Sept. 13, 1966, Ser. No. 579,148 Claims priority, application Germany, Sept. 17, 1965, W 39,937 Int. Cl. B04b 11/08 U.S. Cl. 233- 4 Claims ABSTRACT OF THE DISCLOSURE Centrifuge adapted to resolve solid-liquid mixtures or multi-component liquid solid Imixtures having several liquid components of different specific gravities, which centrifuge has a chamber having a liquid and a solid outlet opening therein and an inlet opening thereto, which inlet opening is positioned along the bottom of the chamber and extends radially into the chamber such a distance as to be adapted to Ibe blocked by the accumulation of solids in the chamber. There is further provided axially disposed means for recirculating feed upon the blockage of said inlet opening and switching means activatable by the recirculating feed whereby to cause sludge discharge from the chamber.

This invention generally relates to the separation of materials `according to their specific gravities. lt more particularly refers to such separations'in which a solid or substantially solid sludge is formed during the separation, which sludge is intermittently or periodically removed frorn the separation apparatus.

The separation of materials according to their specific gravities is well known. Centrifugal separations of this type are widely practiced in industry. Solids are separa-ted from liquids by this technique. It is also possible to separate heavier liquids from lighter liquids by this technique. In many of these separations, a solid sludge is accumulated within the separator bowl, and various methods have been proposed by the art for removing this sludge from the system, preferably during centrifuge operation and without impairing this operation. For example, German Patent No. 1,173,030 describes a process whereby the automatic desludging of a centrifugal separator is accomplished through the use of the contents of the centrifuge as the means of determining when desludging is required. According to this patent, when one component of the material being separated reaches a predetermined depth, a signal is transmitted which initiates the desludging operation. This desludging usually is accomplished by means of a sliding piston which opens or closes orifices in the periphery of the centrifuge bowl. These orifices are opened or closed by manual or automatic operation, depending upon the sophistication of the process, in individually selected or predtermined intervals. In the process of the above-referred to German patent, the liquid level of the heavier component in the sludge chamber is used Ias the means for initiating sludge removal.

It is an object of this invention to profvide a novel apparatus in which an automatic desludging operation can be accomplished.

It is another object of this invention to provide a novel control means for initiating automatic desludging of the centrifugal separator.

Other and additional objects of this invention will become apparent from a consideration of this entire specification, including the claims and the drawings appended hereto.

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In accord with the fulfilling these objects, this invention resides, in one of its aspects, in an apparatus for separating lighter from heavier components, wherein there are provided means whereby the feed material to such separator is caused to act upon a control means which initiates a desludging operation when the sludge level in the separator reaches a predetermined position.

This invention will be Ibetter understood by reference to the accompanying drawings, in which:

FIG. l is an elevational cross-section of a centrifugal separator adapted to resolve a mixture of one liquid and solids into their components; and

FIG. 2 is an elevational cross-section of a centrifugal separator adapted to resolve a mixture of at least two liquids and solids into their components.

Referring now to these drawings, and more particularly to FIG. 1 thereof, the material to be resolved flows from a supply reservoir 1 through a feed tube 2 into a central chamber 3, whereupon this material passes through passage 4 into a separating chamber 5, during which passage the material flows around the periphery of a bottom plate 6. During operation of the centrifuge, the chamber 5 becomes filled with solids, whereupon the opening 7 between the bottom plate 6 and the bottom of the chamber 5 becomes closed 0E to further introduction of feed material therethrough. As the opening 7 becomes closed, the liquid level in the central chamber 3 moves toward the axis of the centrifuge until the liquid level fully immerses the stationary skimming disk 8, whereupon the skimming disk 8 begins to pump the contents of chamber 3 into the feed tube 2 through the channel 9. This pumped liquid returns through opening 10 into chamber 3. This circulatory movement causes a back pressure to develop in the feed tube 2 and causes the incoming feed material to rise through the conduit 11 into contact with a fioat valve 12, which float valve bridges the terminals 13, thus causing the sludge removal operation to be initiated.

The peripheral portion of the bottom plate 6 can project into chamber 5 as far as the sludge level is desired to reach.

The skimming disk 8 prevents the chamber 3 from flooding. Air bleed holes 14 are provided in the skimming disk to prevent formation of air cushion in chamber 3 which would cause interference. Further, if desired, the orifice 10 in the feed tube 2 can be closed, thus relying upon the passage 9 to pass the feed material'into the chamber 3.

Referring now to FIG. 2, substantially the same feed procedure operation is provided as shown in FIG. 1. However, in FIG. 2, the device is specifically adapted to the resolution or clarification of liquid feed, composed of at least two liquids, and solids. Therein is provided a separation plate 15 and a second outlet 16 for the liquid having the greater specific weight. In this device, as the sludge builds up in the chamber 5, it closes channels 17 between the separating plate 15 and the centrifuge bowl cover, thereby prohibiting the heavier uid from discharging through the outlet 16. As the heavier liquid collects in the chamber 5, it rises to the level of the inner surface of the ascending passages 18 and effectively blocks the entry of the lighter fluid into the plate stack. When this occurs, the liquid level in the central chamber rises, and in the same manner as described with respect to FIG. 1, the float 12 is raised to bridge the terminals 13 and institute the desludging operation.

The desludging operation itself can be accomplished in any of the prior art manners such as by means 12 and 13 which either set a known kind of control equipment into operation or oper-ate directly a yvalve in a pressure line leading to the hydraulic system for opening and closing the centrifuge bowl.

What is claimed is:

1. In a centrifugal separating device adapted to resolve a mixture of components at different specic gravities, having an inlet opening for feeding material to be separated thereto, lat least one outlet opening for the removal of a liquid therefrom, peripheral means for removing an accumulated sludge therefrom; and a centrifugal chamber means; the improvement which comprises so positionng said inlet opening along the bottom of said separating chamber such that the build-up of sludge in said chamber will block said inlet opening and will prevent the introduction of feed material into said chamber, means for recirculating feed material upstream of said separation chamber, land switching means activatable t0 initiate desludging of said chamber by operation of said feed material on the switching means.

2. The improved apparatus as claimed in claim l, wherein said separating chamber has a second liquid outlet which is adapted to discharge a heavier liquid from said separating chamber, and wherein said second liquid outlet is adapted to be blocked by the accumulation of sludge in said chamber, which blockage is adapted to cause the activation of said switching means through a feed material.

3. The improved apparatus as claimed in claim 1, wherein said centrifuge has a skimmer disk in the feeding means in communication with said inlet opening and adapted to recirculate said feed material.

4. The improved apparatus `as claimed in claim 3, wherein said skimmer disk is located on an inlet pipe and in an inlet chamber in said centrifuge.

References Cited UNITED STATES PATENTS 3,167,509 1/ 1965 Steinacker 233-20 3,301,476 l/l967 Hemfort 233-20 3,360,194 12/1967 Wilsmann 233-20 HENRY T. KLINKSIEK, Primary Examiner.

U.S. Cl. X.R. 233-45 

